1. Field of the Invention
The present invention relates to a camera having an anti-vibration mechanism to compensate for vibrations affecting the camera and, more particularly, to improvements in (a) the placement of anti-vibration sensors, (b) the connection between components of the anti-vibration mechanism, (c) the connection between the anti-vibration mechanism and external testing devices and (d) the connection of the camera to a tripod.
2. Description of the Related Art
A camera can be exposed to a significant amount of vibration during photography. For example, hand tremors and external forces exerted on the camera can cause vibrations which greatly reduce the quality of the resulting photographs. Therefore, some cameras are equipped with vibration correction mechanisms which adjust for vibrations affecting the camera. Conventional vibration correction mechanisms typically include a photographic optical system having an anti-vibration lens which is adjustable in a direction orthogonal to the optical axis of the camera, and a pair of anti-vibration sensors which detect vibration in the pitch and yaw directions, respectively, of the camera. The anti-vibration lens is adjusted by a CPU in accordance with vibrations detected by the pair of anti-vibration sensors. In this manner, the movement of the anti-vibration lens compensates for the vibrations affecting the camera.
The anti-vibration sensors are relatively large as compared to other sensors and actuators provided in the camera. In addition, each anti-vibration sensor requires a respective space inside the camera. Therefore, the camera size becomes large. Also, it is a problem finding space for other components inside the camera. For example, cameras typically use a battery and a main capacitor to generate an electronic flash. The battery and the main capacitor are also relatively large components as compared to other camera components. Thus, the use of anti-vibration sensors with a battery and a main capacitor tend to increase the camera size and create component placement problems.
Moreover, as illustrated in FIGS. 1 and 2, the anti-vibration sensors 54 and 55 are both mounted on the same sensor card 81, but a CPU (not illustrated) for performing vibration compensation is mounted on a separate flexible circuit card (FPC) 82. The CPU is electrically connected to the anti-vibration sensors by connecting the FPC 82 to the sensor card 81 via a press connection. Thus, sensor card 81 has a connection portion 81a. The camera body has a fixed portion 91, a protruding portion 91a and a protruding portion 91b. The sensor card 81, the FPC 82, a compression rubber 83 and a compression plate 84 are layered in succession on fixed portion 91 and held by a fixing screw 85 which is screwed into fixed portion 91. In this manner, a pattern on the FPC 82 and a pattern on the sensor card 81 are electrically connected so that outputs of the anti-vibration sensors 54 and 55 can be provided to the CPU.
However, as shown in FIG. 2, the pressure connection between the sensor card 81 and the FPC 82 requires that the fixing portion 91 be located on the back surface of the sensor card 81. Therefore, electrical components cannot be mounted on the back surface of the sensor card 81. Also, the pressure connection requires a large amount of space on the component mounting surface of the sensor card 81 and, as a result, the amount of space on the component mounting surface of the sensor card 81 is restricted. The sensor card 81 must be made relatively large if a plurality of electrical components are to be mounted on the sensor card 81.
Furthermore, the vibration correction mechanism must be tested during manufacture or repair. During testing, the anti-vibration sensors and the anti-vibration lens drive mechanism must be connected in a subassembly state to external testing devices. The camera is tested and controlled by these external testing devices. Similar testing connections are required to test focus adjustment mechanisms, rangefinding mechanisms and photometry mechanisms.
The anti-vibration sensors 54 and 55 and the anti-vibration lens drive mechanism are frequently arranged so that they are partially positioned around the photographic lens barrel and towards a front surface side of the camera body. The sensor card 81 is generally mounted in a location between the front cover and the camera body. Therefore, probes functioning as terminals of the external testing devices must be applied to the anti-vibration sensors 54 and 55 and the anti-vibration lens drive mechanism from the front side of the camera.
Two methods are generally used to connect the probes to the anti-vibration sensors 54 and 55 and the anti-vibration lens drive mechanism. In a first method, the front cover of the camera is removed so that the sensor card 81 and contact point terminals on the sensor card 81 are completely exposed. The probes are then applied to the contact point terminals. However, this method cannot be adopted with a camera having the front cover integrally formed with the camera body.
Furthermore, many camera covers have windows formed therein. These windows typically have optical properties to provide a filtering effect or a lens effect and are used as a viewfinder or to receive light for autofocus functions. These windows can experience shifts in precision depending on whether or not the front cover is removed. Thus, the first method of testing is not used when the front cover is integrally formed with the camera body or when the front cover has windows formed therein.
In the second method, a hole is made in the front cover and the probes are inserted through the hole to make contact with the contact point terminals on the sensor card 81. Therefore, this second method can be used with a camera having a front cover integrally formed with the camera body or with a camera in a fully manufactured state. However, it is difficult to perform testing through this hole. Also, it is necessary to conceal the hole by a concealing member, thereby increasing camera cost and design effort.
Moreover, inserting the probes through the hole can cause a deformation of the camera body and inaccurate detection signals from the anti-vibration sensors 54 and 55.
Cameras with an anti-vibration function can also experience problems when fixed to a tripod and performing time exposures (that is, exposures with a shutter speed which is slower than normal). Force is exerted on the camera when the shutter release button is manually pressed. This force causes vibrations. Thus, when the camera is fixed to a tripod and time exposures are performed, a remote operation device is typically used to release the shutter without directly touching the camera body or directly pressing release button. The remote operation device includes a cable release device which uses a cable that must be attached to the camera body while the camera is fixed to the tripod. Therefore, a connection member is necessary to connect the cable to the camera body. This connection member increases the camera cost and also requires a relatively large amount of space for a connector on the camera body. Also, the use of a cable release requires a significant amount of preparation by the photographer. Further, the cable represents another item which the photographer must carry.